Stop motion for knitting machines



Jam, 17, 1950 R. H. LAWSON STOP MQTION FOR KNITTING MACHINES Filed May 1, 1947 2 Sheets-Sheet l INVENTOR ROBERT H. LAWSON By his ailarneys Jan. 17, 1950 LAWSON 2,495,067

STOP MOTION FOR KNITTING MACHINES FiledMay l, 1947 2 Sheets-Sheet 2 lNVENTOR ROBERT H. LAWSON 6 his aiiarneya Patented Jan. 17, 1950 STOP MOTION FOR KNITTING MACHINES Robert H. Lawson, Laconia, N. 11., assignor to Scott & Williams, Incorporated, Laconia, N. -H., a corporation of Massachusetts Application'May 1, 1947, Serial No. 745,170

11 Claims.

This invention relates to. a stop motion for a knitting machine, and more particularly a. knitting machine in which the knitted fabric isv wound upon a shaft. The invention is especially useful in: connection with underwear knitting machines, to which use, however; it. is not restricted.

Inknitting; machines. making continuous fabrics. such as tubular fabric for underwear, it is necessary to stopthe machine periodically to remove the accumulated fabric; Such fabric is customarily rolled up as the knitting progresses and it has heretofore. been known to determine the. proper moment'for stopping the machine by the. size. of the roll of accumulated fabric. It is important for subsequent operations such as dyeing'that the: amount of fabric in each successive roll be uniform, but automatic measurement of the roll diameter as a means of determining when the machine should be automatically stopped, have not proved wholly satisfactory. The measur ing. element tendsto sink into the fabric and become inaccurate particularly when the fabric contains tuck or other fancy stitches. Also, the diameter and radial resistance of the rolls tend to: vary giving rise to further inaccuracy.

I have now found that the weight of the roll may be employed to stop the machine and to insure that a uniform quantity of the knitted fabric will be removed with each roll. Thus subsequent operations upon each roll (as the dyeing operation) may be performed with certainty and with uniform results.

The. invention is shown by way of illustration in its applicationto an underwear knitting machine in, the accompanying drawings in which Fig. 1 is a. perspective view of the frame of a machine towhich the invention is applied,

Fig. 2 is a broken front elevation of the apparatus illustrated in Fig; 1, and

Fig. 3 is an enlarged side elevation of the con trol. apparatus employed.

In the embodiment of the invention which is illustrated in the drawings, there is shown the base ill and legs II and I2 of an underwear knitting machine. In this the knitted fabric 13 extends downwardly to a pair of the usual fabric take-up rolls [4 and [5, between which it passes. Continuing thence, the fabric passes upwardly over a feeler bar I16 controlling the rate at which the fabric. iswound. upon the roll, in av manner forming" no partof: the present invention. heaving the feeler bar, the fabric moves downwardly and wound into: a roll I! upon a. shaft H3. The shaft is. carried bythe two legs H and 12 of the end l'9 supported upon the leg H by a bracket 20, and. a cylindrical idler end 2| supported upon the leg I! in a manner later to be described. The. driven end of the shaft is square in crosssection, and its end fits loosely into av squarerecess. axially formed in a. bushing 22 on the end of a stub shaft 23 journaled in the bracket The driven end of the shaft I8 is prevented from moving axially out of the socket in the bushing 2:21 by a collar 2.4 fixed to.- the shaft inside the support of: the cylindrical idler end of the shaft. A gear 25 on the other end of the stub'shaft meshes with a gear 28 upon the axle of a sprocket wheel 21. A sprocket chain 28, driven from the mechanism of the knitting machine, turns the sprocket wheel 2T and the meshing gears to roll up, the knitted fabric upon the shaft l8.

The idler end 2| of the shaft 18 is. supported fromthe leg [2 by a weighing apparatus which is best shown in Fig. 3. A bracket 29' is fixed to the leg, l2 in any known. or convenient manner. As here shown, a. counterbalanced lever 39 is pivoted to the bracket 29 by means, of a fulcrum screw 3.! which passes through the lever and is fixed in thebracket 29. A notch 32 inthe top of the short end of the lever 30 supports. the idler end 2! of the. shaft, which turns freely in the notch. An adjustable counter-weight 33 isslidably mounted upon the long end of the. lever lit-and may be fixed in adjusted position thereon by means of a set. screw 34. Thus, the weight of the shaft I8 and the. roll I"! thereon tends to depress the short end of the. lever 3!] in which the notch 32 is formed, whereas the adjustable weight 33 tends to counteract the turning moment applied to the lever 3.0. by the weight of the shaft. and roll.

When the knitted'fabric begins to roll up on the shaft [8, the adjustable weight 33 overbalances the weight of the shaft and the roll, thereby causi'ng the long end of the lever to bear upon a lower limit screw 35 turnable in a lug 36 formed on the bracket 29' and extending beneath the lever 30. As the knitted fabric is rolled upon the shaft [8 and the size and weight of the roll [1 increases, the moment about the fulcrum screw 3| in opposition to that of the adjustable weight 33 increases until finallythe long end of the lever rises and comes to rest against an upper limit screw 31. This screw is threaded through an upper lug 38 which extends from the bracket 29' above the lever 30; It will be apparent that the lever is responsive to the weight of the knitted fabric on the shaft l8.

The distance ofthe adjustable weight 33Jfrom knitting machine. The: shaft 18' has a driven theful'crum screw 3.l;issetin such away thatthe 4 lever 30 will rise and contact the upper limit treated with confidence in identical manner in a screw 31 when the desired weight of knitted fabsucceeding operation. rlc has been rolled upon the shaft l8. At this The form of the invention here particularly depoint, it is desired to stop the machine in order scribed and illustrated is presented merely to inthat the roll I! may be removed from the shaft 5 dicate how the invention may be applied. Other l8 and a new quantity of fabric rolled thereon. forms and embodiments of the invention which Various arrangements may be provided for come within the proper scope of the appended Stopping the machine when the lever 30 is overclaims will, of course, suggest themselves to those balanced by the weight of the roll of fabric on skilled in the knitting machine art. the shaft 18. Such arrangements may include 10 Whatis claimed is:

switches for opening or closing auxiliary circuits, 1. In a knitting machine, a shaft upon which latches which may be tripped by the lever, comthe knitted fabric is rolled up, and a pivoted lever pound lever arrangements, and a variety of mechfor stopping the machine supporting one end of anisms well-known in the mechanical and electhe shaft, said lever being responsive solely to the trical arts. Furthermore, such arrangements weight of the knitted fabric on said shaft regardmay be employed in obvious ways to stop knitting less of the size of the roll.

machines which are not electrically driven. 2. In an electrically controlled knitting ma- In the illustrative embodiment shown in the chine, a shaft upon which the knitted fabric is drawings, a micro-switch 39 is mounted upon the rolled up, and a counterbalanced lever for affectbracket 29 in such a way that the lever 30 will 0 ing the operating electrical circuit of the machine close the circuit through it when it rises to conto stop it, one end of said lever supporting one tact the upper limit screw 31. As here shown, an end of the shaft, said lever being responsive solearm 40 extends from the micro-switch 39 to the ly to the weight of the roll of knitted fabric on top of the lever 30 between the fulcrum screw said shaft regardless of the size of the roll.

and the adjustable weight thereon; and the arm 3. In an electrically controlled knitting ma- 40 bears upon the lever resiliently at all times. chine, a shaft upon which the knitted fabric is The construction of the micro-switch is such that rolled up, a lever supporting one end of said shaft when the lever 31] rises suiiiciently to meet the responsive to the weight of the knitted fabric upper limit screw 31, the arm 40 will close the rolled thereon, and a normally open switch actucircuit through the micro-switch. A wire 4| conated by said lever to break the operating circuit nects the micro-switch to the control box 42 of of the machine. the machine; and the control box and the micro- 4. In a knitting machine, a shaft for rolling switch are both grounded to the frame of the and accumulating the knitted fabric, adrive from machine. Consequently, by closing the circuit the main machine for rotating said shaft, a through the micro-Switch, it is possible to oper- 3 weighted lever supporting one end of said shaft, ate a stop motion either to break the circuit which and a contact responsive to movement of said operates the machine or to disengage the clutch lever to disconnect the power supply of the ma of the machine. chine.

Operation of the apparatus will be apparent. 5. In a knitting machine, a shaft for receiving Having determined the amount of the knitted and rolling the knitted fabric, parts driven elecfabric to be periodically removed from the matrically adapted to turn said shaft, a weighted chine and hence its weight, the adjustable weight lever supporting one end of said shaftfand a 33 is positioned upon the lever 30 so as to balance switch contact operable by said lever to break the this weight exactly. The set screw 34 is next electrical circuit of said electrically driven means tightened to fix the position of the weight. The 4 When the weight of the said fabric on said'shaft underwear knitting machine is then started overbalances said weighted lever.

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through the control box 42 and the knitted fab- 6. In aknit in m chi e, n l ri l op ra i ig is 11 d upon th shaft 13 until th ed circuit, a shaft upon which the knitted fabric is termined weight is carried thereby. Thereupon, ll up, and a driving connection for said shaft the lever 30 turns in a clockwise direction (as 5 53 111 ggg g fi viewed in the drawings) about the fulcrum screw 1 g r a 3|, closing the circuit through the micro-switch p W Supporting One end'of Said Shaft, 21 39 and stopping the machine, Th knitt d fab i normally open switch controlling said electrical is then cut between the take-up roll [5 and the Operating circuit and mechanical connection fabric r011 The fabric 1.011 n is removed 55 between said switch and said lever for closing the from the shaft l8 and the cut end of the fabric is circuit through sfaid Switch and Stopping the fastened to the shaft. The underwear knitting mQEChme P Sam lever 15 overbalanced, byihe machine is then started again, and the roll which g Z g g-achm a s a p w ich th shaft [8 is advanced 1 z fi lifggsfig g ggfi The loose driving fit the knitted fabric is rolled up, a driving connecbetwzen the square driventindbw Iof thgzshaft I: :32 i piagg g z'gi g iigfizi gg q ggs 2 3 31? and he square recess in e us ing permi the shaft to be easily removed and replaced. Furg g g ig zsggg i sg g g g i ggggi a thermore, since the cylindrical ldlel end 2| of thi machine and a mechanical connectionybetween zgg g g gi ii fi g fgg g gsfi g; i s jggg said switch and said lever for closing said switch to stop the machine when said lever is overbalfrom the machine without disturbing the position anced by the weight on Said shaft of the collar 24 upon g? g ig 2 g 8. In an electrically-driven knitting machine, a therefore be t a y ac 2 s. shaft, a driving connection from the machine for Thus the kmttmg machme 15 au y rotating said shaft and rolling knitted fabric stopped whenever a predetermined quantity of thereupon, a pivoted lever supporting one end the kmtted fabric has been accumulated. Each of said shaft a counter..weight on said lever for roll which is f m d po the Shaft l thereoverbalancing the weight of'said shaft and the fore of the same weight and Size and may b roll of knitted fabric thereon up to a critical weight, and a normally open switch operable by said lever to stop the machine when the counterweight thereon ceases to overbalance the weight of said shaft and the roll of knitted fabric thereon.

9. In an electrically-driven knitting machine, a shaft, a driving connection from the machine for rotating said shaft and rolling knitted fabric thereupon, a pivoted lever supporting one end of said shaft, an adjustable counter-weight on said lever for overbalancing the weight of said'shaft and the roll of knitted fabric thereon up to a critical weight, and a switch operable by said lever to stop the machine when the counterweight thereon ceases to overbalance the weight of said shaft and the roll of knitted fabric thereon, substantially as described.

10. A method of stopping a knitting machine in which knitted fabric is rolled up on a shaft supported at one end by a pivoted lever, comprisingthe steps of rolling up the fabric on the shaft without regard to the size of the roll and employing solely the Weight of the roll to tip the lever, whereby the machine is stopped with a predetermined quantity of fabric on the shaft.

11. A method of stopping an electrically driven 6 knitting machine in which knitted fabric is rolled up on a shaft supported at one end by a pivoted lever, comprising the steps of employing parts driven by the said knitting machine to roll the fabric, and automatically breaking the electrical circuit when a predetermined weight of the fabric has been rolled by tipping the lever solely by the weight of the fabric, whereby the machine is stopped with a predetermined quantity of fabric in the roll.

ROBERT E. LAWSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 55,332 Merriam et a1 June 5, 1866 1,016,009 Herbert Jan. 30, 1912 1,029,756 J amieson June 18, 1912 1,499,449 Dorn et al July 1, 1924 2,384,288 Eddy Sept. 4, 1945 2,418,444 Wytovich Apr. 1, 1947 

